[PATCH] drm/shmem-helpers: vunmap: Don't put pages for dma-buf

[Thomas Zimmermann]

Hi

Am 19.02.21 um 13:22 schrieb Noralf Trønnes:
> dma-buf importing was reworked in commit 7d2cd72a9aa3
> ("drm/shmem-helpers: Simplify dma-buf importing"). Before that commit
> drm_gem_shmem_prime_import_sg_table() did set ->pages_use_count=1 and
> drm_gem_shmem_vunmap_locked() could call drm_gem_shmem_put_pages()
> unconditionally. Now without the use count set, put pages is called also
> on dma-bufs. Fix this by only putting pages if it's not imported.
> 
> Fixes: 7d2cd72a9aa3 ("drm/shmem-helpers: Simplify dma-buf importing")
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>

Just when I saw the error. Nice. :)

Acked-by: Thomas Zimmermann <tzimmermann at suse.de>
Tested-by: Thomas Zimmermann <tzimmermann at suse.de>

For testing the GUD driver, you may also want to keep an eye at [1]

Best regards
Thomas

[1] 
https://lore.kernel.org/dri-devel/02a45c11-fc73-1e5a-3839-30b080950af8@amd.com/T/#t

> ---
>   drivers/gpu/drm/drm_gem_shmem_helper.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
> index 9825c378dfa6..c8a6547a1757 100644
> --- a/drivers/gpu/drm/drm_gem_shmem_helper.c
> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
> @@ -357,13 +357,14 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
>   	if (--shmem->vmap_use_count > 0)
>   		return;
>   
> -	if (obj->import_attach)
> +	if (obj->import_attach) {
>   		dma_buf_vunmap(obj->import_attach->dmabuf, map);
> -	else
> +	} else {
>   		vunmap(shmem->vaddr);
> +		drm_gem_shmem_put_pages(shmem);
> +	}
>   
>   	shmem->vaddr = NULL;
> -	drm_gem_shmem_put_pages(shmem);
>   }
>   
>   /*
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature
Type: application/pgp-signature
Size: 840 bytes
Desc: OpenPGP digital signature
URL: <https://lists.freedesktop.org/archives/dri-devel/attachments/20210219/45d770c1/attachment.sig>